Irreversible Capital Investment in a Two-Stage Bimatrix Fishery Game Model

A two-stage, two-player noncooperative game model is developed(under an irreversible capital investment assumption) with the main aim of predicting the number of vessels that each player in such a game will find in his best interest to employ in the exploitation of the Arcto-Norwegian cod stock, given a noncooperative environment and the fact that all players are jointly constrained by the population dynamics of the resource. The predictions so obtained are then compared with (i) the sole owner's optimal capacity investments for the two players; (ii) the results in Sumaila (1994), where perfect malleability of capacity is assumed implicitly: and (iii) available data on the Acrto-Norwegian cod fishery.noncooperative, game, fisheries, irreversible, capital, trawl, coastal, Environmental Economics and Policy,

A BIOECONOMIC ANALYSIS OF THE NORWEGIAN SPRING SPAWNING HERRING (NSSH) STOCK

A biological model belonging to the Beverton-Holt age-structured family for the Norwegian spring spawning herring (Clupea harengus) (NSSH) is simulated, the outcome of which compares well with actual data on the fishery. This model is then combined with an economic model to help investigate how optimal a management policy of constant fishing mortality will be for a fishery such as the NSSH, which has a highly fluctuating stock biomass. For the range of constant values of fishing mortality explored, and a simulation time horizon of 20 years, a constant fishing mortality of 0.15 turns out to be economically optimal. It should be noted that this result is sensitive to variations in the assumptions underlying key variables of the fishery. For example, when a constant rather than variable recruitment was assumed, a different optimal fishing mortality rate was obtained.bioeconomic model, herring optimal management, Resource /Energy Economics and Policy, Q57, Q22, Q28,

NATURAL RESOURCE ACCOUNTING AND SOUTH AFRICAN FISHERIES: A BIO-ECONOMIC ASSESSMENT OF THE WEST COAST DEEP-SEA HAKE FISHERY WITH REFERENCE TO THE OPTIMAL UTILISATION AND MANAGEMENT OF THE RESOURCE

Resource /Energy Economics and Policy,

Topical Problems in Fishery Economics: An Introduction

Resource /Energy Economics and Policy,

Trade and sustainable fisheries

The ultimate goal of this contribution is to formulate fish trade policy recommendations that can be deployed to help achieve the relevant Sustainable Development Goals of the United Nations (SDGs). Even though all the 17 SDGs are relevant to the issues addressed in this contribution, I will focus on SDG14: Life under the water, and also SDG 1 (No poverty); 2 (Zero hunger); 3 (Gender equality); 4: (Reduced inequality); and 12 (Responsible consumption and production). Before I get to the recommendations, I will review the literature on the relationship between fish trade and sustainable fisheries; and discuss the potential promise (pros) and perils (costs) of fish trade. Policy recommendations for using fish trade to support the SDGs are provided under different headings that capture the main concerns highlighted in the literature when it comes to ensuring the sustainability of fisheries in general and those related to the impact of trade on fisheries sustainability in particular. The policy measures presented in this chapter have the potential to help ensure that trade in fish and fish products would support the implementation of the SDGs

ON THE DYNAMICS OF COMMERCIAL FISHING AND PARAMETER IDENTIFICATION

This paper has two main objectives. The first is to develop a dynamic model of commercial fisheries different from most existing models that assume optimizing behavior. The industry is assumed to have a well-defined index of performance. Based upon this index, the decision to invest or not is made. We do not, however, assume that the industry or firm is efficient or optimal in its operations. The second is that a new approach of fitting model dynamics to time series data is employed to simultaneously estimate the poorly known initial conditions and parameters of nonlinear fisheries dynamics. The approach is a data assimilation technique known as the variational adjoint method. Estimation of the poorly known initial conditions is one of the attractive features of the variational adjoint method.Resource /Energy Economics and Policy,

Trade-based estimation of bluefin tuna catches in the Eastern Atlantic and Mediterranean, 2005-2011

The Eastern Atlantic and Mediterranean stock of Bluefin tuna Thunnus thynnus (BFTE) has long been considered overfished and at risk of collapse. Although ICCAT quotas for this stock have decreased considerably over the past years, uncertainty exists about the degree of catch beyond this quota. The extent of such catch is an important piece of information in stock assessment models as well as being an indicator of the effectiveness of fisheries management. We present a model using Bluefin tuna trade data to infer actual catches. Basing our calculations on 25 countries involved in BFTE trade, we estimate that between 2005 and 2011, allowable quotas were exceeded by 44 percent. This gap between catch and quotas has slightly increased over past years, leading to estimated excess catches of 57 percent for the period between 2008 and 2011. To improve assessments, preparation and design of BFTE management, we suggest that the estimated total removals reported in this paper be included in stock assessment models for BFTE. An implication of our findings is that ICCAT member states should take stronger measures to monitor and enforce compliance with quotas

Impact of management scenarios and fishing gear selectivity on the potential economic gains from Namibian hake

This paper develops a model for Namibian hake, which incorporates the biology, gear selectivity and the economies of the hake fisheries in a framework that allows the analysis of fishing gear impacts on the potential economic gains from the resource. The objective is to produce quantitative results on the key variables of the fishery, namely economic rent, standing biomass and catch levels, that will support the optimal sustainable management of one of Namibia's most valuable fishery resources. Outcomes for three management scenarios are produced, (i) command; (ii) cooperative; and (ii) none-operative. For each of these, results are presented for two different assumptions of the economic setting under which the managers of the fishery operate, that is, a fully economic setting and a setting with cost-less labour inputs. As would be expected, different management scenarios and assumptions about the economic setting impact on the results derived from the model in significant ways

Protected Marine Reserves as Fisheries Management Tools: A Bioeconomic Analysis

This paper develops a dynamic computational bioeconomic model with the objective of assessing protected marine reserves as fisheries management tools. Data on the North East Atlantic cod stock are used to determine the bioeconomically optimal size of a marine reserve for the Barents Sea cod fishery, as a function of the net transfer rate between the protected and unprotected areas of the marine habitat. The single agent model developed, allows for the occurrence of a shock to the system in the form of severe recruitment failure in the non-protected area. Two key results emerge from the study. First, establishment of marine reserves are bioeconomically beneficial when net transfer rates for cod are "reasonably" high and reserve sizes are large: Large reserves provide good protection for the stock in the face of the shock, while high transfer rates make the protected fish available for harvesting after the shock has occurred. Further, optimally chosen reserve size when net transfer rates are high, also mitigates against biological losses. Second, when net transfer rates are low, the establishment of marine reserves does not mitigate against losses in discounted economic rent, while they tend to be efficient in mitigating against biological losses